Imprimatura Dorata
ProductInformation Primer I & II
lmprimatura Dorata is the recreation of a renaissance wood primer and sealer system.
The individual ingredients that it is based on were once employed by various industries, arts and crafts.
Under influence of the advances made in the practical sciences, traditional production methods for many materials - including those used to formulate lmprimatura Dorata - were rationalised towards the end of the l8th century.
This resulted in more uniform, reliable and cheaper products. The unique property of colouring white woods golden was lost in this rationalisation, because it was the result of the way in which some of the original processes were run and the (even today not yet entirely understood) organic chemistry involved.
Organic processes by their very nature strive to achieve a balance and therefore usually yield balanced mixtures of a large variety of organic and inorganic chemical compounds. These are neither the most effective nor the most reliable for any specific single purpose chemical reaction. The priming of wood however was not done for a single purpose, and possibly not even primarily to achieve the optical effects that we still admire today. The colouring and ossifying properties that made the traditional products so useful as wood primers, were at best unimportant side effects to other users of these raw materials. Not many luthiers would have been equipped to realise what was causing the changes in their primers. If any did; they could not have afforded the luxury of experiment or worry for any length of time. In any case; even the demand from a larger number of luthiers would not have been sufficient to continue the traditional production methods for their exclusive use.
In our opinion these factors made later speculations about lost or secret recipes almost inevitable.
The optical effects caused by Imprimatura Dorata are mainly the result of interactions between the primer (and to a lesser extent the sealer) and natural organic compounds in the wood. In coniferous woods it is mainly dimethoxystilbene which interacts with lmprimatura Dorata. In properly harvested pine the highest concentration of this compound is found in the winter growth. This explains the pronounced colouring of the read lines. With the woods natural chemicals playing a major role in the colouring, it can be understood that their distribution throughout the timber (which stands in direct relation to the season and method of harvesting) is related to the evenness of the final result. Just as the quality of this result may vary with the quality of each individual piece of wood; not unlike the variation seen on classical instruments.
MAGISTER Imprimatura Dorata PRIMER III MAGISTER Imprimatura Dorata SEALER
Clear liquid primer Clear liquid-resin sealer
Colour: yellow brownish Colour : pale gold
PH : 6 - 8 PH : not applicable
Packaging: 100 & 250 ml plastic bottle Packaging : 100 & 250 ml plastic bottle
Ready to use: solvent Alcohol/Water mixture Ready to use : solvent oil of Turpentine
lmprimatura Dorata primer and sealer system colours all white woods golden, shows up pine winter growth orange - red brown and darkens the modulary ray speckles in maple
Hardens the wood, protects the wood fibres against dirt and seals them without filling the pores
Over a longer period of time Imprimatura Dorata primer gradually ossifies the wood fibres
Primed surfaces (not sealed) can be glued with ordinary hide glues
Lightly glue soaked areas (e.g. purfling) and end grain will also be coloured evenly
Can be used underneath both oil and spirit varnish systems
Expose 4 - 7 days to the warmth of the summer sun for optimum results (or 8 - 24 hours in a drying cabinet) Use ordinary U.V.A. suntan tube lights. Approx. 250 Watt/m³, for example4 x 80 Watt in a 1.5 m³ cabinet.
Minimum storage time 12 months at 5 - 15 C, keep away from direct light sources
Does not cause health or environment hazards when used according to standard hygienic and industrial safety procedures (see below)
Does not contain any heavy metals above the levels that occur in most natural organic matter
KEEP OUT OF REACH OF CHILDREN - ! USE ANY VARNISH MATERIAL ONLY IN A WELL VENTILATED ENVIRONMENT
! DO NOT INGEST ANY VARNISH - ! IN CASE OF SKIN CONTACT WASH WITH PLENTY OF WATER AND SOAP
! FOR SKIN AND EYE PROTECTION WEAR SAFETY GLASSES AND RUBBER GLOVES
Disclaimer : Our products are made with the outmost care. However; once they have left our premises we no longer control their correct use and safe handling. Magister V.P. can therefore not accept any liability connected to the use or handling of their products.
Imprimatura Dorata
ApplicationInstructions Primer I & II
1.Finish the instrument with scrapers and burnish it with the stems of the wetland plant “horsetail” this is sometimes also called “shaving grass” (DE Schachtelhalm)
2.Pour approx. 30ml. of PRIMER (for one violin) into a clean, well closable glass jar. Never work from the original container! Store left-over separate to avoid contamination.
Also see the additional information!
3.Apply 1 - 2 coats of PRIMER to soft woods, and 2 - 3 coats to hard woods, preferably with a flat, soft bristle brush (avoid skin contact) Leave 15 minutes drying time in between coats.
4.After the last coat hang the instrument in the sun for a day (or a drying cabinet for about 7 hours).
If your result is not strong enough you can apply more primer and repeat the sunning procedure.
The wood may now appear slightly reddish and/or a little brighter in colour than the final result will be. Brushes can be cleaned with an alcohol and water mixture (1 : 1)
5.Apply 1 or 2 coats of SEALER (usually 2 on softwoods) Leave 2 hours drying time between coats
6.After the last coat of SEALER expose the instrument to the direct warmth (and light) of the summer sun for 3 - 5
days. Alternatively 8 - 16 hrs. in a drying cabinet will also do.
Use standard U.V.A. suntan tube lights (e.g. Philips “Cleo performance Advantage“) approx. 250 Watt/m³
Divide the cabinet time into several 4 hour sessions. And give your instrument 1 session every 12 hours.
During this curing time the wood colour will tone down into a golden-yellow.
The instrument is now ready to be varnished with an oil or spirit varnish method.
! Instead of using a separate sealer, you can also let the by us suggested “ground” (Vernice Liquida +
Pumice powder) double up as sealer. We believe this to be the case with many classical instruments,
especially those where the ground shows only very little tendency to chip away from the wood.
Ad 1.This procedure is important for the reflective quality of the wood and evenness of the primer application. We have seen the markings of horsetail on several classical instruments with the aid of a stereomicroscope at high magnifications under special lighting conditions. Horsetail contains silica. As you progress with the burnishing this gets pushed into the surface of the wood. You will notice that the wood quickly acquires a silvery shine and becomes more “mirror“ like.
The smoothness of surfaces treated this way is of an entirely different character to that left by even the finest grade of sandpaper! Burnishing does not need to take more than 15 minutes for a violin.
Take special care to finish open grained woods as smoothly as possible. lmprimatura Dorata PRIMER will lightly raise the grain; if this is undesirable you can wet and scrape down the wood before starting the burnishing. If a gesso/filler type of ground is used after sealing this should not be necessary.
Ad 3.Apply the coats quickly and evenly, moistening the whole surface, go over the same spot several times without refilling the sponge or brush too often. 2 coats are advisable for evenness.
In most cases 3 - 4 coats will produce more pronounced results.
Give maple one extra coat because it takes on less primer per coat than pine.
Ad 4.Missed spots can be retouched during drying
Ad 5. It is not necessary and even strongly advised against trying to achieve a shiny, varnished looking surface with the sealer. Many classical instruments testify to the fact that their coloured varnishes were still able to enter the pores of the wood even after a ground was applied between the sealer and coloured varnish. After sealing the wood should still look like unsealed wood! You can dilute the sealer with petroleum (sometimes also called paraffin- kerosene lamp oil) turpentine or lavender oil.
Ad 6.When the curing is finished (5 - 7 days) the surface can be smoothened again with shaving grass or pumice and drying oil (clean off the oil afterwards)
Important : Do not apply PRIMER or SEALER in humid conditions.
To make sure you are satisfied with the final results; always make a test piece on the same material that you are going to varnish; some woods (especially coniferous) may give a less even result when harvested in summer or containing excessive amounts of (iron) stain.
MAGISTER cannot warrant against this. also see additional information below.
The wood's natural oxidation products can also react with lmprimatura Dorata.Because oxidation is much stronger in end grain areas it is not advisable to use old wood, or to suntan before priming.
Imprimatura Dorata
AdditionalInformation Primer I & II
The quality of European timber used for constructional and fine woodwork was of great importance until at least the start of massive imports of colonial hardwoods. Maybe as a direct result from this there seems to have been a change in the standard harvesting method. By the middle of the 18th century some advocated a return to the “old" method of debarking (ring barking) a tree one winter and not cutting it down until the next winter. A ring barked tree will use up all of it's remaining saps in trying to produce foliage, and literally starve to death. A Dutch study by C.J.Krayenhoff publicized in 1760 proves the resulting timber to be more woodworm, fungus and dry-crack resistant, stronger and ready for use within one or two years after being cut down.
This may well have had a positive effect on the acoustical qualities of the wood. It would certainly explain why classical makers never seem to have run into the only problem which you may experience with lmprimatura Dorata. Some pine reacts strongly to l. D. which is why we advise you to make a test piece.
(hard woods never cause a problem because their saps are of a very different chemical composition)
If the winter growth of your test piece goes very deep red or even the summer growth colours orange-red, the wood was most likely not harvested when the sap was low (in winter).
In most cases you can remedy this by one of the following changes in your application procedure.
2a. Before you start the priming, quickly moisten the pine with petroleum or turpentine on a lint free cloth.
2b. Rub down with a dry cloth. Proceed with point 3. Or alternatively
2a. Wet the pine with water before priming (this will have a larger influence on the surface texture of the belly)
Next proceed with point 3.
If you want to go as save as possible! adopt one of these changes as a standard procedure
The effect of l.D. largely depends on the individual piece of wood, but can be manipulated to a degree by the number of coats applied and smoothing / filling operations done before, during or after priming and sealing.
Also the composition and thickness of the ground and/or varnish can influence the appearance of l.D. underneath.
In our opinion the next (and sometimes the only following) step in the classical system was to provide an even surface with an oil-varnish based ground. This was then finished with the same or a very similar varnish.
The various oil varnishes used for this purpose were available at most apothecary shops throughout the middle ages and well into the classical period of violinmaking (at least until 1670) They were generically known as "Vernice Liquida”. Vernice Liquida was made in many different varieties. Some of these were almost regarded as a basic ingredient for all kinds of formulations themselves. When the right filler material is added to the right type of Vernice Liquida (finely ground pumice powder seems to have been the preferred material) it will serve as a transparent gesso which can be used to even out all irregularities in the woodwork. On drying, this gesso will form a very stable and wear resistant ground. The pumice powder has the added advantage of enhancing the optical activity of the varnish. By acting as tiny prisms, the silica particles will bend and scatter the light rays in every direction, changing their quality. This will happen both on their way into and out of the varnish, adding to an overall lively appearance of this varnish. Obviously the sheer quantity of light reflected by the wood surface is important in this process. Therefore the structure of the wood and the treatment of it’s surface even prior to the priming (no sandpaper!) also play a role in the appearance of the final varnish. See application instructions Ad 1
The differences between traditionally made Vernice Liquida type varnishes and later oil varnishes are primarily caused by differences in the preparation of raw ingredients and recipe formulation and manufacture criteria.
When properly made, Vernice Liquida type varnishes have good flow characteristics and are self levelling.
They will form an extremely tough yet flexible varnish film, with a soft and warm feel to it. This and their slower drying rate caused the discontinuation of their use in the middle of the 18th century. Some of the higher quality uncoloured Vernice Liquida types - like our “Comune” and “Glassa” varieties - form dry varnish layers that exhibit the typical ivory-white fluorescence of classical grounds under UV light.
For coloured varnishes we suggest the use of Doratura varnishes (gold varnishes) with or without the addition of pigments. In thin layers on silvery metals these appear like different shades of gold.
Thicker layers on wood will show much more variation.